By shooting hard plastic balls at sheet metal membranes, their impact turns a plain surface into a spatial sculptural object. This embossing-technique was first realized for the sound installation „Prägung“, a collaborational work of Harald Christ and Sonice Develoment in 2011. In a circular process, the rebounding plastic balls are captured by nets, fed back into the machine by a conveyor and re-shot at the sheet metal. The artwork evolving from the two-dimensional membrane is the thousand fold cast of the bullets pressing their three-dimensionality into it. „Prägung“ was presented at Ars Electronica in Linz 2012.